When Kevin Systrom and Mike Krieger sold their company for $US1 billion in 2012 to Facebook, they hadn’t even worked out how to make money.

Now, according to analyst forecasts, Instagram is on track to bring in $US8 billion in ad revenue this year.

Studies and estimates show that Instagram is generally growing faster than the core Facebook app, and gets more engagement from users.

Facebook can’t afford to let that growth stall.

Instagram has turned out to be the best purchase Facebook ever made.

The camera-oriented social network is, according to a Bloomberg analysis, now worth around $US100 billion. Facebook bought the company for just $US1 billion in 2012, marking a 100-fold return on its investment.

All of this proves that Instagram is hugely important to Facebook’s future growth, not least because the brand is still comparatively untainted. Facebook’s main app has been marred by scandals around privacy, the Cambridge Analytica issue, and the spread of fake news.

Tied with this, Instagram is also increasingly popular with brands, who benefit from Facebook’s sophisticated targeting capabilities and the popularity of Instagram with a hard-to-reach younger demographic.

Systrom and Krieger might be gone, but Facebook can’t afford to let the golden egg crack.